7,702 research outputs found
Evaluation of selected chemical processes for production of low-cost silicon, phase 3
A Process Development Unit (PDU), which consisted of the four major units of the process, was designed, installed, and experimentally operated. The PDU was sized to 50MT/Yr. The deposition took place in a fluidized bed reactor. As a consequences of the experiments, improvements in the design an operation of these units were undertaken and their experimental limitations were partially established. A parallel program of experimental work demonstrated that Zinc can be vaporized for introduction into the fluidized bed reactor, by direct induction-coupled r.f. energy. Residual zinc in the product can be removed by heat treatment below the melting point of silicon. Current efficiencies of 94 percent and above, and power efficiencies around 40 percent are achievable in the laboratory-scale electrolysis of ZnCl2
Three-Dimensional Simulations of Solar and Stellar Dynamos: The Influence of a Tachocline
We review recent advances in modeling global-scale convection and dynamo
processes with the Anelastic Spherical Harmonic (ASH) code. In particular, we
have recently achieved the first global-scale solar convection simulations that
exhibit turbulent pumping of magnetic flux into a simulated tachocline and the
subsequent organization and amplification of toroidal field structures by
rotational shear. The presence of a tachocline not only promotes the generation
of mean toroidal flux, but it also enhances and stabilizes the mean poloidal
field throughout the convection zone, promoting dipolar structure with less
frequent polarity reversals. The magnetic field generated by a convective
dynamo with a tachocline and overshoot region is also more helical overall,
with a sign reversal in the northern and southern hemispheres. Toroidal
tachocline fields exhibit little indication of magnetic buoyancy instabilities
but may be undergoing magneto-shear instabilities.Comment: 14 pages, 5 color figures, to appear in Proc. GONG 2008/SOHO XXI
Meeting on Solar-Stellar Dynamos as Revealed by Helio and Asteroseismology,
held August 15-18, 2008, Boulder, CO, Astronomical Soc. Pac. Conf. Series,
volume TB
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Evidence from Meteosat imagery of the interaction of sting jets with the boundary layer
Meteosat infra-red imagery for the Great Storm of October 1987 is analysed to show a series of very shallow arc-shaped and smaller chevron-shaped cloud features that were associated with damaging surface winds in the dry-slot region of this extra-tropical cyclone. Hypotheses are presented that attribute these low-level cloud features to boundary-layer convergence lines ahead of wind maxima associated with the downward transport of high momentum from overrunning, so-called sting-jet, flows originating in the storm's main cloud head. Copyright © 2004 Royal Meteorological Society
Marriage and housework
This article provides insights into the gains of forming a couple by estimating how much of the difference in housework between single and married individuals is causal and how much is due to selection. Time-varying observed variables and time-invariant heterogeneity explains about half of the observed differences in housework documented in the cross-sectional data. There remains a genuine one-and-a-half-hour increase per week in housework time for each partner, with women specializing in routine and men in non-routine housework tasks
Inoculate for More and Better Soybeans
For many years the experiment station folk, we of the Iowa Station included, have been telling you to inoculate your soybean seed. But just how much increase in yield can you expect from inoculation, and will it improve the quality of the crop produced
Marriage and Housework
This paper provides insights into the welfare gains of forming a couple by estimating how much of the difference in housework time between single and married individuals is causal and how much is due to selection. Using longitudinal data from Australia, UK and US, we find that selection into marriage by individuals with a higher taste for home-produced goods can explain about half of the observed differences in housework documented in the cross-sectional data. There remains a genuine two-hour increase in housework time for each partner upon marriage, with women specializing in routine, and men specializing in non-routine housework tasks
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